Noronhia armandiana

Hong-Wa, Cynthia, 2016, A taxonomic revision of the genus Noronhia Stadtm. ex Thouars (Oleaceae) in Madagascar and the Comoro Islands, Boissiera 70, pp. 1-292 : 47-48

4. Noronhia armandiana Hong-Wa, spec. nova ( Fig. 5 ).

Typus : M ADAGASCAR. Prov. Fianarantsoa: Atsimo-Atsinanana, Farafangana, Mahabo-Mananivo , forêt d’Agnalazaha , 23°08’42”S 47°42’18”E, 31 m, 22.IV.2004, Ludovic 759 (holo-: MO-6615572!; iso-: G, P, TAN) .

Diagnosis

Noronhia armandiana Hong-Wa can be distinguished from its congeners by its dense branching, its whitish bark, its oblong leaf blades and its rounded fruits.

Description

Trees to 13 m tall, trunk to 15 cm diameter; young twigs cylindrical, 1-1.5 mm diameter, glabrous; bark light gray, smooth. Leaves opposite, persistent; bud scales persistent; blades dark green above, lighter below, oblong, 5.5-10.5 3 1.5-3.5 cm, coriaceous, glabrous, domatia rare, base attenuate, margin revolute, apex shortly cuspidate, the cusp 5-10 mm long, midrib slightly sunken above, distinctly raised below, secondary veins barely visible, 7-12 per side, 6-12 mm apart, looping 1-4 mm from the margin; petiole light gray, 4-8 3 1-2 mm, entirely woody, glabrous. Flowers fasciculate; pedicel 3-5 mm long, moderately pubescent; calyx moderately pubescent outside, glabrous inside, lobes triangular, 1 3 1.8 mm; corolla reddish brown, urceolate, 4.8 mm long, glabrous on both sides, the tube 3 mm long, lobes ovate, apex rounded; corona present, 1.5 mm long, undivided; stamens 1.8 mm long, anthers oblong, 1.2 mm long; pistil 1.8 mm long, stigma capitate. Fruiting pedicel 6-8 3 1.2-1.8 mm; young fruits green, dark brown when mature, globose, 12-15 3 12-15 mm, surface covered with white dots, apex flat to bluntly pointed; dry pericarp 0.9-1.6 mm thick; endocarp crustaceous; seed 7-8.7 3 5.5-8.3 mm.

Etymology

This name honors Armand Randrianasolo, Curator at the Missouri Botanical Garden in St. Louis, for his dedication to the conservation of the Malagasy flora and particularly for his role in the conservation of Agnalazaha forest, where the type specimen was collected.

Distribution, ecology and phenology

Noronhia armandiana occurs in littoral to low-elevation humid forests at Manombo in the east ( Fig. 3 ). It produces flowers and fruits from November to April.

Conservation status

Noronhia armandiana is currently known only from four collections representing four localities. With an EOO of 42 km 2, an AOO of 12 km 2, and three subpopulations representing three locations, none of which occurs in a protected area, although one is located just outside Manombo RS, N. armandiana is assigned a preliminary status of “Endangered” [EN B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)]. Areas outside of Manombo RS have been gradually converted into agricultural land, reducing the suitable habitat available to this species. In addition, wood harvesting and sporadic wildfire such as that of 2005, which burned 200 ha of forest (BIRKINSHAW et al., 2005), also constitute a substantial threat.

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Notes

Noronhia armandiana most closely resembles N. marinae Hong-Wa, from which it differs by its oblong (vs. linear to lanceolate) and shortly cuspidate (vs. acuminate) leaf blades. Its flowers are fasciculate, urceolate and reddish brown (vs. thyrsoid, cupuliform and purplish pink) and its fruits have a flat (vs. apiculate) apex and crustaceous (vs. woody) endocarp. This species can be recognized by its dense branching, whitish bark, oblong leaf blades, and rounded fruits.

Paratypi

MADAGASCAR. Prov. Fianarantsoa: Forêt Classée near Manombo RS, 23°03’16”S 47°40’28”E, 100 m, 15.XI.2001, McPherson & Rabenantoandro 18419 ( MO, TEF); Farafangana, Mananivo , Iabomary , 23°03’34”S 47°40’23”E, 0-50 m, 6.II.2001, Rabenantoandro et al. 442 ( G, MO, P, TAN); Mahatsinjoriaka , [23°02’10”S 47°44’50”E], 0-10 m, 28.II.1956, Service Forestier 16264 ( P, TEF) .

Figures

Fig. 5. Noronhia armandiana Hong-Wa. A. FLowering branch; B. FLower; C. Inner side of coroLLa; D. LateraL view of corona; E. PistiL; F. Stamen.

Fig. 3. Distribution maps of species of Noronhia Stadtm. ex Thouars: N. alleizettei Dubard to N. capuronii Bosser.